yet another version of the java script solution: LaTeXMathML which I've had good success. I just put it up on one of my own servers and linked to it in my blogger template. It suffers from the same drawbacks -- lag in rendering, doesn't render in feeds, etc. But there it is.

I think a good solution for me right now would be to do markup offline so that I don't have an external dependency. Maybe I can borrow the guts of one of these javascript solutions to do that. The problem then is to find a subset of outputs that is visible by, say, 95% of readers without forcing them to download fonts. I guess I can just post another test. I already have a markup of my own that handles some simple TeX type stuff to convert things like \Delta, ^ and _ to lowest common denominator HTML.